Hybrid cars could be almost five times dirtier than battery-powered electric cars, new report finds

A new assessment of the full life-cycle emissions of four commonly used powertrains in passenger cars in the United States has found that battery electric vehicles (BEVs) have significantly lower full life-cycle greenhouse gas (GHG) emissions than all other powertrains.

The new detailed assessment of vehicle life-cycle emissions was conducted by the International Council on Clean Transportation (ICCT) as an update to a 2021 analysis that at the time found that “the life-cycle emissions of electric vehicles… are already lower than those of a comparable gasoline car” in Europe, the United States, China and India.

A new analysis estimates the full life-cycle emissions of internal combustion engine vehicles (ICE), hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV) and battery electric vehicles (BEV) – for both sedans and SUVs. The results show that the advantage of electric vehicles has increased.

A 2021 ICCT study found that the full life-cycle greenhouse gas emissions of the average midsize electric vehicle sold in the United States in 2021 were between 57 and 68 percent lower than those of internal combustion engine vehicles – depending on the average carbon intensity of the electricity grid.

The latest assessment found that the life-cycle emissions of 2024 BEV sedan models in the United States are between 66 and 70 percent lower than those of conventional ICE vehicles (depending on the average grid carbon intensity), while the life-cycle emissions of 2024 BEV SUV models are between 71 and 74 percent lower than those of competitive ICE vehicles (depending on the same conditions).

This figure increases even more when the grid is powered by 100% electricity from renewable sources, reaching 83 and 85 percent respectively.

Although both electric hybrids and plug-in hybrids have better performance than vehicles with internal combustion engines, they are significantly inferior in terms of performance to battery electric vehicles (BEV).

The ICCT assessment found that the full life-cycle emissions of model year 2024 PHEV sedans are 40 percent lower than those of internal combustion engine models, while for SUVs, emissions are 44 percent lower than conventional internal combustion engine models, and for HEV SUVs, emissions are only 27 percent lower.

This means that PHEV sedans and SUVs in 2024 will have about twice the emissions of BEVs powered by a standard energy mix, and for HEVs, an estimated 2.2 times higher emissions for sedans and 2.5 times higher for SUVs.

The news is even worse for hybrid vehicles, whose grid is powered by 100% electricity from renewable sources, which increases the life-cycle CO2 emissions of hybrid vehicles compared to electric vehicles up to 4.9 times.

ICCT predicts that new vehicles sold in 2030 will show an even wider gap. Conventional SUVs are estimated to have 7.5 times higher life-cycle greenhouse gas emissions than BEVs powered by 100% renewable electricity.

While hybrid and plug-in hybrid vehicles (HEVs) will have a smaller carbon footprint than internal combustion engine vehicles, the ICCT states that “their emissions reduction potential is more limited than that of battery electric vehicles (BEVs), which not only provide emissions reductions at the tailpipe but also over the life of the vehicle for typical sedans and SUVs sold in the United States.”

Joshua S. Hill is a Melbourne-based journalist who has been covering climate change, clean technology, and electric vehicles for more than 15 years. He has been covering electric vehicles and clean technology for Renew Economy and The Driven since 2012. His preferred mode of transportation is feet.